The field of the invention is in the manufacturing processing of integrated circuit (IC) chips, including IC packages and dies with transistors, interconnects and other microscopic elements and structures, and processing of printed wiring boards. The field of the invention also involves the printed wiring boards, IC packages, and IC dies themselves, as well as smart power devices, digital computers and data processing systems.
Without limiting the scope of the invention its background is described in connection with chip fabrication.
Advanced VLSI chips are typically built with layers of metalization. The metal layers are separated by insulators which can typically be CVD (chemical vapor deposition) oxides. Polyimides have been proposed as interlayer dielectrics. These compounds may be applied by spinning and then are cured at temperatures between 300.degree. C. and 350.degree. C. This process produces a planar surface that is ideal for metallization. In the past, however, it has been found that organic compounds have limited thermal stability at elevated temperatures (e.g., &gt;300.degree. C.) and are porous to moisture penetration. See Sze, VLSI Technology, 2nd ed., p. 267 (1988).
Due to the widespread applications of IC (integrated circuit) chips, improvement is desirable in their manufacture to even further increase reliability and yields and to reduce costs.